clear;
clc;
format long;
H=hilb(4);
H1=inv(H),
norm(H*H1-eye(4))

H2=invhilb(4);
n=norm(H*H2-eye(size(H)))

H=hilb(10);
H1=inv(H);
n1=norm(H*H1-eye(size(H1)))
H2=invhilb(10);
n2=norm(H*H2-eye(size(H)))


H=hilb(13);
H1=inv(H);
n1=norm(H*H1-eye(size(H1)))
H2=invhilb(13);
n2=norm(H*H2-eye(size(H2)))
H=sym(hilb(7));
H1=inv(H)

H=sym(hilb(30));
norm(H*inv(H)-eye(size(H)))
